Represents the remaining building on the Atlanta, Georgia headquarters lease.

No definition available.

Name:	bxc_OccupiedBuildingHeadquartersLease
Namespace Prefix:	bxc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the space remittance fees payable with respect to this unoccupied space.

+ References

No definition available.

+ Details

Name:	bxc_SpaceRemittanceFeePayable
Namespace Prefix:	bxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the unoccupied building formerly part of the Atlanta, Georgia lease on the headquarters building.

+ References

No definition available.

+ Details

Name:	bxc_UnoccupiedBuildingHeadquartersLease
Namespace Prefix:	bxc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cash outflow for the allowance granted to lessee and/or direct costs incurred by lessor used to prepare the leased premises for tenant's occupancy.

+ References

No definition available.

+ Details

Name:	us-gaap_PaymentsForTenantImprovements
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_RestructuringCostAndReserveLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying amount as of the balance sheet date of improvements having a life longer than one year that were made for the benefit of one or more tenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.1(f))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

Name:	us-gaap_TenantImprovements
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Restructuring Charges (Detail Textuals) (2007 Facility Consolidation and Severance Costs, USD $) In Millions, unless otherwise specified	3 Months Ended			12 Months Ended
	Sep. 29, 2012	Mar. 31, 2012	Oct. 01, 2011 Building	Dec. 29, 2012 Building
2007 Facility Consolidation and Severance Costs
Restructuring Cost and Reserve [Line Items]
Tenant improvement allowance included in Selling, general, and administrative expenses	$ 0.9
Tenant improvement allowance included in Other current liabilities and Other non-current liabilities				0.3
Number of unoccupied buildings			4,100
Space remittance fee payable		$ 5.0
Number of occupied buildings				4,300